Monellin is an intensely sweet protein that occurs naturally in the berries of the West African plant Dioscoreophylllum cumminsii. It is approximately 100,000 times sweeter than sucrose on a molar basis, or about 300 times sweeter than the dipeptide sweetener aspartame. Experimental evidence shows that the intact three-dimensional structure of monellin is required for it to elicit the sweet response, and most of the research effort expended on studying monellin has focused on trying to understand the structural basis for this protein's extraordinary sweetness. The structure of natural monellin has been determined using x-ray crystallography and refined to 2.75 w. From structure comparison among these analogs, we would like to refine our understanding of the interactions between monellin and its receptor that trigger the sweet response.